they want tsarnaev treated as an enemy combatant under the laws of war. lester? >> michael isakoff, thank you. for more on the government's attempts to find out what motivated these suspects, we're joined by nbc's chief foreign affairs correspondent, andrea mitchell. in our washington bureau, andrea? >> good evening, lester. intelligence officials, the fbi, a global search for what motivated tamerlan tsarnaev's terrorism. was it chechnyan nationalism, at the white house today, the president met again in the situation room with his national security advisers. he was briefed by the fbi director and top counterterrorism officials and others for 0 minutes. an official tells us afterwards that so far, there is no evidence of foreign involvement, but they're looking. they also say they are getting good cooperation now from russia, with whom as you know the u.s. has had very rocky relations over the last few years. russia's president vladimir putin spoke with president obama last night and the two leaders are discussing the importance of working more closely together on